Mechanism of formation of half-doped stripes in underdoped cuprates

摘要

Using a variational Monte-Carlo approach with a recently proposed stripe wavefunction, we showed that the strong correlation included in a t-J-type modelhas essentially all the necessary ingredients to form these stripes withmodulations of charge density, spin magnetization, and pair field. If aperturbative effect of electron-phonon coupling to renormalize the effectivemass or the hopping rate of holes is considered with the model, we find thehalf-doped stripes, which has on the average one half of a hole in one periodof charge modulation, to be most stable, energetic wise in the underdopedregion, $1/12\leq\delta\leq1/8$. This is in good agreement with the observationin the neutron scattering experiments. We also find long range Coulombinteraction to be less effective in the formation of half-doped stripes.